Given the current condition of the locomotive with LNER buffers, low dome set further back on the Dia. 50A boiler and lack of the safety valve cover it would be historically incorrect to to paint it in anything other than LNER or British Railways black!
When it entered service in early December 1918 it is most likely to have received the post March 1917 livery which, following an instruction, was for all goods and mineral locomotives to be painted black, without lining or heraldry. It would also have had a small 9 in by 5 in cast iron number plate on the cab side together with the number being painted in large yellow, shaded red, figures between the letters 'N' and 'E' (with stops) on the tender side. The large cast brass number plate fitted when the locomotive was previously painted in North Eastern livery was not correct as all such plates were removed from goods, mineral and shunting engines in 1917.
It would be nice to see the T2 cosmetically restored to something like its as built condition by replacing the LNER buffers and dome and adding the low safety valve cover and cast iron number plates so that NER livery could be justified but will the NELPG go to these lengths?

I don't care if this loco and others have been modified and modernised in ways that cannot readily be un-done to accurately and fully portray original condition. They still deserve to appear in the classic liveries of the original owning companies and the pre-nationalisation era in general. There's far too much these days in 50s/60s livery, done purely to appeal to a current mass of aged former train spotters and viewers of Heartbeat etc.

Most subjects, models and techniques covered in this thread are now listed in various categories on page1

Dec. 2018: Almost all images that disappeared from my own thread following loss of free remote hosting are now restored.

I agree Graeme. Too often the "it wouldn't be historically accurate" argument is used to justify the keeping of pretty much everything in BR guise. Given most locomotives in preservation saw service in their BR guise, this argument could pretty much be applied unilaterally, as almost every locomotive would require some degree of modification to return it to its pre-grouping or big four state. Of course there is the argument that obviously there is more mk1 stock about, so there is some sense in having a full train that "matches." I do rather enjoy, for example, Swanage's recreation of the BR era. However even that will be altered with their overhaul of the T3, which cannot appear in anything later than SR guise.

It seems bizarre that the only locomotive operating in LNER Apple green with LNER on the tender is the B12. It was certainly nice to see 1264 go back in time a little, despite "historical inaccuracy." That being said, all things go in phases, and in the last 5 years or so there seems to be a push back towards pre-grouping liveries. I will patiently await the cycle to roll back round to big four era liveries, probably led by the P2 (which thankfully can appear in no other guise for those who use the historically accurate bludgeon - mind you I've still heard a few say it'd be nice to see what a P2 would look like in BR guise )